Band strapping machine



J. v. PRESTW'ICH BAND STRAPPING MACHINE July 20, 193 7.

Filed Aug. 24; 1935 5 Sheets-Sheet l INVENTOAE. My 63 fEJ/JATT Y July ZO, 1937. JpV. PRESTWICH BAND STRAPPING MACHINE 5 Sheets-Sheet 2 Filed Aug. 24, 1935 296 was 52 y 0, 1931. J. v. PRESTWICH 2. 87.655

BAND STRAPPING MACHINE Filed Aug. 24, 1955 5 Sheets-Sheet 5 Jahn vnvl qn E'QS'I'W/tk l NVENT'O E,

Q WM;

y 1937- J. v.- PRESTWICH I 2,087,655

BAND STRAPPING MACHINE Filed Aug. 24, 1935' 5 Sheets-sheaf 4 INVEN-ro July 20, 1937. I

J. v. PRESTWICH 2,087,655

BAND STRAPPING MACHINE Filed Aug. 24,1935 5 sheets-sheet 5 John vn /a an wres+wlck INVBNT E 61 4;. A 'Y- I Patented July 20, 1937 UNITED STATES ANT QE'FEQE BAND STRAPPING MACHINE John Vivian Prestwich, Tottenham,

London,

England 10 Claims.

This invention relates to improvements in band strapping machines, such as are used for tensioning strapping bands and uniting the overlapping ends thereof. The chief objects of the present invention are, firstly, to provide a simple and small machine which will be easy to operate and emcient in use and, secondly, to provide improved means for tensioning the band and for releasing the same after the sealing has been effected.

The band strap sealing machine according to the present invention comprises essentially a tensioning and gripping device in conjunction with one or more movable die members adapted to co-operate with a like number of corresponding fixed die parts on the anvil of the machine, the die member or members being controlled by one or more cams operated by a lever which, when it is thrown over to separate the die members, automatically releases the end of the band from the tensioning gripping device.

Means are, of course, provided to sever the band from the supply after the seal has been made, and the cutter is preferably carried by the moving die member, as hereinafter explained.

The preferred form of tensioning device according to the present invention comp-rises two sets of gripping devices, each so mounted as to allow movement of the band in one direction whilst preventing it in the other direction, one

of these sets being fixed and the other being movable.

. In order that this invention may be the more clearly understood and readily carried into effect, I will proceed to describe the same with reference to the accompanying drawings, which illustrate by way of example and not of limitation one convenient embodiment of this invention, and in which Figure l is a front elevation of the machine, and

Figure 2 is a plan view of the machine.

Figure 3 is a longitudinal vertical section through the same showing the die member raised and the operating lever engaging the tensioning gripping device.

Figure 4 is a local section through the sealing portion of the machine showing the die member in its depressed position.

Figure 5 is an end elevation of the machine showing a catch device to position the overlapping parts of the band.

Figure 6 is a view similar to Figure 5 showing the automatic release of the catch device after the seal has been effected.

Figure? is a fragmentary perspective view illustrating a clip or ratchet device for holding the operating handle.

Figure 8 is a somewhat diagrammatic view i1- lustrating the action of the tensioning device.

Figure 9 is a fragmentary front elevation illustrating the action of the band gripping device.

Figure 10 is a detailed elevationushowing a modified form of cutter.

Figure 11 is a section on line H-H of Figure 1 illustrating the mounting of the cutter block.

Figure 12 is a local sectional View through one part of the base showing a means ofadjusting the cutter block.

Referring now to the drawings, the band strap sealing machine is adapted to seal the band in the manner described in my co-pending patent application No. 17,475 filed April 20, 1935, now

issued as Patent 2,059,906, dated Nov. 3, 1936, 20

and the same comprises a base 28 which is provided with rearwardly projecting lugs 21 which thus form a rigid support for the whole machine. At one end of the machine is mounted the sealing device which comprises a die member 22 Zr slidably mounted between side guides 23 and enclosed between these side guides by means of a fixed back plate 24 and a removable front cover 25. The die member 22 has screwed, or otherwise fixed to its lower edge the die 26 which is constituted by two male and two female die- I parts spaced apart and arranged in accordance with my co-pending patent application above referred to. This die member 22 is adapted to be operated by means of a cam 21 which is housed within an aperture 28 in the die member 22 and mounted on a short shaft 29 journalled in the back plate 24 and the front cover 25. This shaft 29 is, to the rear of the back plate 24, provided with a long lever or handle 30. The die member 22 is provided with an inset roller 3! on which the cam 27 bears, and, above the cam 21, is provided with a spring-pressed plunger 32 which tends to keep the die member 22 raised against the action of gravity. The spring pressed plunger 32 thus ensures that the roller 3! is always kept in contact with the cam 21. The cam 21 is also so shaped relative to the aperture 28 that on its return movement it imparts a definite lift to the die member 22. 50

The corresponding die member 33 co-operating with the die 26 above referred to comprises two female and two male die-parts spaced apart and is screwed, or otherwise suitably fixed, tothe base 20 of the machine. I

The base of the machine, or the lower die member, is provided with two spaced projections 35, one on each side of the die-parts across which the band 35 is stretched so that normally the band is free of the male die-parts. This arrangement will ensure that the sealed band will not stick to the lower die-part 33, since the tension of the band, which is obtained in a manner hereinafter described, will tend to stretch the band 35 in a straight line between the projections 55 and so will free the band from the die parts after sealing.

In use, the free end of the band 35 is slipped between the die-parts and 33 and then is gripped by means of a gripper at that end of the machine remote from the sealing device. This gripper (see Figure 9) comprises a knurled roller 35 eccentrically mounted in the back plate 3'! of the machine and controlled by means of a handle 38 on the back of the machine. The handle 33 is thrown to one side or the other to grip or release the band 35 (see the bro-ken line and full line positions of Figure 9), the grip being obtained between the knurled roller 35 and the base 26 of the machine.

With the band 35 thus gripped, the free end lies freely over the projections 3 34 and between the die-parts 26 and 33. The band'is then passed around the case (not shown), again slipped in between the dies 25 and 33 and then passed to the tensioning and gripping device 53, 53, 5?, 51, which will be hereinafter described. At that end of the machine remote from the gripper 35 is arranged a pivoted catch device 39 having a rearwardly projecting tail 4!) (Figure 5) located in the path of the handle 35 (see Figure 6), this catch device being adapted to take over the superimposed parts of the band to hold the same in such a position that they are correctly'located between the die-parts 25 and 33.

After tensioning, the upper of the two parts of the band lying between the projections as, 34 is secured to the lower part, which is not under tension, by forcing down the die 22, the same operation causing the band to be severed from the supply as hereinafter described.

In passing to the tensioning device the upper band passes, of course, over the cutter block 4| which is slidably mounted in a slot 52 in the back plate of the machine and is spring-pressed upwards by means of a spring 53 which is located in the back plate, the cutter block projecting forwardly over the base. The band, when tensione-d as hereinafter described, bears on the cut ter block and presses the same down against the action of the spring.

The object of mounting the cutter block 5! in the slot 52 and controlling the same by the spring 43 is to give a certain amount of yielding when the cutter first engages with the upper band. As the cutter continues to descend it presses the upper band and the cutter block down until finally the cutter block comes into contact with the lower band and the base, whereupon the upper band is cut and, as the tension is thereby released, the two overlapping parts of the band slide relatively to one another and the seal is ob-. tained by the interengagement of the tongues and apertures.

In order to compensate for wear and tear on the cutter an adjustable. stop in the base under the forwardly projecting part of the cutter block may be provided to limit the downward movement of the cutter block. In use the lower part of the band is, of course, disposed over the stop. Such a stop is shown at mil, Figure 12, and is adjusted by means of the screw llll. The cutter 44 may form part of the die-part 25, as shown in Figure 3, or, alternatively, it may be a separate member (Figure 10) which is adjustably mounted on the side of the die member 22. In the construction shown in Figure 10 a screw 65 passes freely down a slot in the side of the die member 22, screws through a block 65, which is held against vertical movement in the die member, and then screws into the cutter. It will thus be seen that by turning the screw 45, the upper end of which is exposed on removal of the front cover 25, the position of the cutter 44 may be'adjusted relative. to the cutter block 4! in order to compensate for wear and tear.

In use, after the band 35 has been positioned and tensioned, the long lever 30 is thrown over to force down the die-part 25 and then returned. At the end of its movement to force down the diepart 25 the long lever engages with the tail 4B of the catch device 39 (see Figure 6) and thus lifts the. catch device free of the overlapping parts of the band in order to facilitate the removal of the machine from the sealed band. Theoverlapped parts of the band will thus be sealed effectively in the manner described in my copending patent application above referred to and the sealed band will be severed from the supply;

As the pointed ends left at the free end of the band by the semi-circular cut will be covered in the next strapping operation, 'no damage is likely to be caused thereby.

Describing now the tensioning device which is one of the characteristic features of the. present invention, this comprises two sets of gripping devices, each so mounted as to allow movement of the bandin one direction whilst preventing it in the other direction, one of these sets (the left hand one in the drawings) being attached to the back plate. 31 as shown in Figs. 1 and 3 and the other being movable with respect thereto.

The movable set is carried by a block 41 which has an extension 48 slidably mounted in bearings 49 located above the gripper 35. Pivoted as at 50 in an upward extension 5| of the frame is a lever 52, the lower end of which engages with the extension 48 on the block t! so that by rocking the lever 52 the block 4'! is moved backwards and forwards. On the block is mounted a lower gripping roller 53 which is concentric with its spindle 54 and quite free. Above this lower roller 53 is pivoted as at 55 an arm 56 which projects downwardly and carries at its end a fixedly mounted knurled roller 51. The arm is nor mally kept in such a position that the two rollers 53 and 51 engage with one another and, by reason of the point of mounting of the arm 55 and its length, these rollers 53 and 57 grip the band so that, whilst it can be pulled through the same away from the sealing device or from left to right on the drawings (this movement tending to separate the rollers), it cannot be pulled through them in the opposite direction, as any tendency towards this movement (from right to left) only tends to cause the rollers 53 and 5'! to bite'more firmly into the band. The means for causing the rollers 53 and 5? normally to contact with one another comprise a compression spring 58 housed in a housing 59 on the block 41 and bearing at its, upper end, through the intermediary of a pad 55, on an off-set part 5! of the arm 55, the spring pressure giving the desired clockwise urge to the arm 56. The off-set part 6| of the arm 55 is provided with a rearwardly extending pin 62 lying in the path of the main operating handle 30.

The other set of parts for the tensioning device is similarly arranged, and corresponding reference characters have been used to indicate like parts, but, of course, this set is carried by the back plate instead of by the sliding block 41. The two pairs of rollers 53 and 57 are so mounted that the band 35 takes a straight line, during the tensioning operation, from the locating device 39 right through the tensioning device.

A cover 63 is provided over the bearings 49 and the pivot 53 and this cover is provided with an outstanding bridge or projection 64 which accurately locates the band at this end of the machine so that it lies correctly between the dieparts.

Initially the main operating handle 30 lies towards the tensioning device and bears on the rearwardly projecting pins 62 on the off-set parts H of the arms 56. A clip device 65 having a projecting tooth 66 is provided to hold the arm or handle 38 in such a position that the pressure of the compression springs is overcome and the upper knurled rollers 51 are moved away from the lower rollers 53 (see Figure 3). The tooth 66 is, when the handle is depressed so as to disengage the tension rollers, adapted to engage with one of the teeth of a rack fitting 6'! which is screwed to the handle 30 at the appropriate part (see Figure 7). With the tooth E6 engaged with the rack 61 the handle 30 will be firmly held and the band 35 may thus be readily inserted between the sets of rollers. The band having been positioned, the main operating lever 38 is raised out of the clip 65 which frees the compression springs and thus causes the band to be gripped (see Figure 8). The tensioning lever 52 is then moved backwards and forwards to tension the band. On its forward movement the tensioning block 41 in moving towards the sealing device has a movement relative to the band which allows the rollers 53 and 51 to move along the band. On the other hand, any tendency of the rollers to move the band forwardly through the fixed pair of rollers is prevented as the fixed rollers grip the band against this movement. This allows the moving set of rollers to take up a grip on the band near the fixed set. When now the block is moved back it must take the band with it since the rollers grip, but the fixed set of rollers allow the band to be drawn through the same.

It will thus be seen that by oscillating the tensioning lever 52 backwards and forwards the band may be tensioned as desired, the two sets of rollers alternately gripping and allowing the band to pass.

After the sealing operation, as described above, the main operating lever 30 is thrown back to its initial position and engaged with the clip, whereupon the upper rollers are moved out of engagement with the lower rollers and the band may be easily removed.

By having the tension device gripping rollers arranged in line with one another and by mounting the block so that it slides backwards and forwards in this line, all chance of the end of the band being curled so as to render it unfit for the next sealing operation is avoided.

The machine according to the present invention is thus simple in design, easy to use and efficient in operation.

I claim:

1. A band strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said last-mentioned means comprising two separable elements, spring means normally forcing said elements together to grip the band and a projection on one of said separable elements extending into the path of movement of the control lever and engaged thereby after the band has been sealed to cause separation of the two elements to release the band.

2. A band strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said last-mentioned means comprising two separable elements, spring means normally forcing said elements together to grip the band, a projection on one of said separable elements extending into the path of movement of the control lever and engaged thereby after the band has been scaled to cause separation of the two elements to release the band, and a clip device to hold said control lever in'engagement with said projection with the separable elements of the gripping and tensioning device separated.

3. A band strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said lastmentioned means comprising a first pair of sep arable and eccentric ally mounted rollers allowing movement of the band in only one direction, spring means normally forcing said rollers together to grip the band, a second pair of separable and eccentrically mounted rollers, said second pair being movable as: a unit and allowing movement of the band only in the same direction as the first pair, further spring means normally forcing said second pair of rollers; together to ,grip the band, means for moving said second pair of rollers backwards and forwards to tension the band, and two projections each operatively connected to one of the rollers of each pair extend: ing into the path of movement of the control lever and engaged thereby after the band has been sealed to cause separation of each of the two pairs of rollers.

4. A band strap sealing machine comprising at least one die member, an anvil block 00- operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said last-mentioned means comprising a first pair of upper and lower, separable and eccentrically mounted rollers allowing movement of the band in one direction only, a pivoted arm carrying the upper roller, spring means normally forcing said rollers together to grip the band, a second pair of upper and lower, separable and eccentrically mounted rollers, said second pair being movable as a unit and allowing movement of the band only in the same direction as the first pair, a further pivoted arm carrying the upper roller of the second pair, further spring means normally forcing said second pair of rollers together to grip the band, means for moving said second pair of rollers backward and forward to tension the band,

and projections on said pivoted arms extending into the path of movement of the control lever and engaged thereby after the band has been sealed to swing said pivoted arms to cause separation of the pairs of rollers to release the band.

5. A hand strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said lastmentioned means comprising a first pair of upper and lower, separable and eccentrically mounted rollers allowing movement of the band in one direction only, a pivoted arm carrying the upper roller, spring means normally forcing said rollers together togrip the band,a second pair of upper and lower, separable and eccentrically mounted rollers, said second pairbeing movable as a unit and allowing movement of the band only in the same direction as the first pair, a further pivoted arm carrying the upper roller of the second pair, further spring means normally forcing said second pair of rollers together to grip the band, means for moving said second pair of rollers backward and forward to tension the band, projections on said pivoted arms extending into the path of movement of the control lever and engaged thereby after the band has been sealed to swing said pivoted arms to cause separation of the pairs of rollers to release the band, and a clip, device to hold said control lever in engagement with said projections with the pairs of rollers separated.

6. A band strap sealing machine comp-rising a die member having therein an aperture, an anvil block co-operating with said die member to seal the band, a cam located within the aperture in said die member and engaging said die member, a spring controlled plunger extending between said cam and said die member to keep the cam in engagement with the die member, a control lever operatively connected with said cam to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said last-mentioned means comprising two separable elements, spring means normally forcing said elements together to grip the band, and a projection on one of said separable elements extending into the path of movement of the control lever and engaged thereby after the band has been sealed to cause separation of the two elements to. release the band.

'7. A hand strap sealing machine comprising a die member, an anvil block co-operating with said die member to seal the band, a cam engaging said die member, a control lever operatively connected with said cam to raise and lower the die member, a cutter, a spring mounted cutter block co-operating with saidcutter to sever the band, means for gripping the free end of the band and means for gripping and tensioning the band, said last-mentioned means comprising a'first pair of separable and eccentrically mounted rollers allowing movement of the band in only one direction, spring means normally forcing said rollers together to grip the band, a second pair of separable and eccentrically mounted rollers, said secondv pair being movable as a unit and allowing movement of the band only in the same direction as the first pair, further spring means normally forcingsaid second pair of rollers together ,to grip the band, means for moving said second pair of rollers backwards and forwards to tension the band, and two projections each operatively connected to one of the rollers of each pair extending into the path of movement of the control lever and engaged thereby after the band has been sealed to cause separation of each of the two pairs of rollers.

8. A band strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a controllever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said lastmentioned means comprising two separable ele-' ments, spring means normally forcing said elements together to grip the band, a projection on one of said separable elements extending into the path of movement of the control lever and engaged thereby after the band has been sealed to cause separation of the two elements to release the band, and a catch device to hold the parts of the band correctly positioned between the die member and the anvil block.

9. A band strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam member to raise and lower the die member, a cutter to sever the band after it has been sealed, means for gripping the free end of the band and means for gripping and tensioning the band, said last-mentioned means comprising a first pair of separable and eccentrically mounted rollers allowing movement of the band in only one direction, spring means normally forcing said rollers together to grip the band, a second pair of separable and eccentrically mounted rollers, said second pair being movable as a unit and allowing movement of the band only in the same direction asthe first pair, further spring means normally forcing said second pair of rollers together to grip the band, means for moving said second pair of rollers backwards and forwards to tension the band, two projections each operatively connected to one of the rollers of each pair extending into the path of movement of the control lever and engaged thereby after the band has been sealed to cause separation of each of the two pairs of rollers, a pivoted catch device to hold the parts of the band correctly positioned between the die member and the anvil block, and a projection on said pivoted-catch device extending into the path of movement of the control lever and engageable thereby to free the band.

10. A band strap sealing machine comprising at least one die member, an anvil block co-operating with said die member to seal the band, a cam member engaging said die member, a control lever operatively connected with said cam memher to raise and lower the die member, a cutter to sever the band after it has been scaled, means for gripping the free end of the band and means for gripping and tensioning the band, said lastmentionecl means comprising a first pair of upper and lower, separable and eccentrically mounted rollers allowing movement of the band in one direction only, a pivoted arm carrying the upper roller, spring means normally forcing said rollers together to grip the band, a second pair of upper and lower, separable and eccentrically mounted rollers, said second pair being movable as a unit and allowing movement of the band only in the same direction as the first pair, a further pivoted arm carrying the upper roller of the second pair, further spring means normally forcing said second pair of rollers together to grip the band, means for moving said second pair of rollers backward and forward to tension the band, projections on said pivoted arms extending into the path of movement of the control lever and engaged thereby after the band has been sealed to swing said pivoted arms to cause separation of the pairs of rollers to release the band, a clip device to hold said control lever in engagement with said projections with the pairs of rollers separated, a pivoted catch device to hold the parts of the band correctly positioned between the die member and the anvil block, and a projection on said pivoted catch device extending into the path of movement of the control lever and engageable thereby to free the band.

JOHN VIVIAN PRESTWICH. 

